Overclocking and 22nm

In the old days, whenever Intel transitioned to a new manufacturing process it was accompanied by increased overclocking headroom thanks to the reduction in power consumption and increase in switching speed afforded by the new transistors. To be honest, it's surprising the ride has even lasted this long.

Intel's 22nm process (P1270) is the most ambitious yet. The non-planar "3D" transistors promise to bring a tremendous increase in power efficiency by increasing the surface area of the transistor's inversion layer. It's the vehicle that will bring Intel into new form factors in mobile, but we're around a year away from Haswell's introduction. Rather than 22nm being a delivery platform for Ivy Bridge, it feels like Ivy Bridge is being used to deliver 22nm.

The process is still young and likely biased a bit towards the lower leakage characteristics of lower voltage/lower wattage CPUs, such as those that would be used in Ultrabooks. These two factors combined with some architectural decisions focused on increasing power efficiency result in what many of you may have heard by now: Ivy Bridge won't typically overclock as high as Sandy Bridge on air.

The frequency delta isn't huge. You'll still be able to hit 4.4—4.6GHz without resorting to exotic cooling, but success in the 4.8—5.0GHz range will be limited to water alone for most. Ivy Bridge is also far more sensitive to voltage than Sandy Bridge. Heat dissipation can increase significantly as a function of voltage, so you'll want to stay below 1.3V in your overclocking attempts.

For the past few years I've been focused on power efficient overclocking. I'm looking for the best gains I can get without significant increases in core voltage. With my 3770K I was able to reliably hit 4.5GHz with only a 140mV increase in core voltage:

The end result is a 15—28% overclock, accompanied by a 32% increase in power consumption. The relationship between overclock speed and power consumption actually hasn't changed since Ivy Bridge, at least based on this datapoint.

Ivy Bridge Overclocking

Intel Core i7 3770K

Stock

4.6GHz Overclock

% Increase

Load Power Consumption

146.4W

204W

39.3%

x264—2nd Pass

41.8 fps

49.5 fps

18.4%

As always, your mileage may vary depending on the particular characteristics of your chip. Ivy Bridge can be overclocked, but at least initially it's not going to be as good of an overclocker as Sandy Bridge. Over time I expect this to improve somewhat as Intel's 22nm process matures, but by how much remains a question to me. It's unclear just how much of these limits are by design vs. a simple matter of process maturity.

As much as I like the idea of decent Skyrim framerates on every laptop, and even though I find the HD4000 graphics an interesting read, I couldn't care less about it in my desktop. Gamers will not put up with integrated graphics - even this good - unless they're on a tight budget, in which case they'll just get Llano anyway, or wait for Trinity. As for IVB, why can't we have a Pentium III sized option without IGP, or get 6 cores and no IGP?Reply

Strategy, they're using their lead in CPUs to bundle it with a GPU whether you want it or not. When you take your gamer card out of your gamer machine it'll still have an Intel IGP for all your other uses (or for your family or the second-hand market or whatever), that's one sale they "stole" from AMD/nVidia's low end. Having a separate graphics card is becoming a niche market for gamers. That's better for Intel than lowering the expectation that a "premium" CPU costs $300, if you bring the price down it's always much harder to raise it again...Reply

There is actually a good reason for both AMD and Intel to keep a GPU on their CPUs no matter what. That reason is OpenCV. This move makes the assumption that OpenCV or programming languages like it will eventually become mainstream. With a GPU coupled to every CPU, it saves developers from writing two sets of code to deal with different platforms.Reply

OpenCV is Open Computer Vision and runs either way. I think you're talking about OpenCL (Open Compute Language). and even that runs fine without a GPU. OpenCL can use all cores CPU + GPU and does not require separate code bases.

Maybe we could actually see some hard numbers before heaping so much praise on Trinity??

I will be convinced about the claims of 50% IGP improvements when I see them, and also they need to make a lot of improvements to Bulldozer, especially in power consumption, before it is a competitive CPU. I hope it turns out to be all the AMD fans are claiming, but we will see.Reply